Secondary Sources Primary vs. Secondary Sources Your instructors may require you to use more primary sources than secondary sources for your research. Discover the identifying characteristics and advantages of primary and secondary and tertiary sources with this guide.
Op-amp circuit builder go to Stage 2 of this interactive flash movie Two ways to make an active one[ edit ] The basic "dynamizing" idea[ edit ] Obviously, we have to reveal the truth by ourselves; let's then begin reasoning.
The problem pops up when we connect a load and, what is worse, if we begin varying its resistance. Note the load may be not only a steady or varying resistor; it might be a capacitor that is charging, a diode ordinary, zener, LED, base-emitter junction, etc.
It is not so important what Usining sources 2 the load is; it is only important that a voltage drop appears across the load and this voltage drop confuses things. If we look around, we can see that most things in this world are changeable, adaptable, dynamic According to this observation, we have to make our current source react somehow to the load "intervention", to resist to its attempt to lower the current.
That Usining sources 2 something inside the current source has to change, in order to compensate the disturbing voltage drop across the load. What can change in this simple electric circuit? In our recipe for current we have two ingredients - voltage and resistance.
Hence, if we want to make our current source react to changes in load, we have to alter one of the two ingredients dynamically, in relevance with the change in load resistance. Making the internal voltage dynamic[ edit ] Fig. Keeping up a constant current by a dynamic voltage source.
One possible solution would be to vary the internal voltage - when the load increases, the internal voltage rises too.
We can call this one dynamic current source with following internal voltage. It may seem like a smart idea, but unfortunately - it is not. It's actually a kind of bootstrapping - this term comes from the story about Baron Munchhausenwho once got stuck in quicksand, and pulled himself up by his own bootstraps.
This solution has quite a limited ability to compensate changes in load, because the varying supply voltage will quickly reach its maximum. Making the internal resistance dynamic[ edit ] Keeping up a constant current by a dynamic resistor. The other possible solution is to vary the internal resistance.
Hence the name of the resistor R is current-stable resistor. Of course, this method also has a limited ability to compensate changes in load resistance, because the decreasing internal resistance will reach zero at a certain time. But it's much more simple to implement it's easier to play with resistance, then messing around with voltage.
We will continue our quest to destination Simplest transistor current source by using the second methodology. What element will we use to materialize the dynamic internal resistance solution? As the name of this topic implies, it's going to be the transistor.
Let's talk about its behavior to find out why Active current source with a BJT[ edit ] What is the transistor and why did we choose it[ edit ] Transistors Enter the transistor - considered one of the greatest inventions of the 20th century.
A tiny device, that literally changed the world and now dominates all areas of life - it can be found in every electronic device around us, as it is the fundamental building block of modern electronic circuits.
OK, the transistor is pretty cool Its name comes from transfer resistor - transistor To keep it short, the transistor is a semiconductor device comprising two PN junctions and has three terminals.
At least that's how they call it, even though it's not amplification at all. Actually, the transistor allows us to control a larger current flow the output with a smaller current flow the input.
It's more like creating a scaled copy of the input signal using additional power, than amplifying it. Think of it as a current valve - valves are devices used to control the flow of a fluid, in our case the current would be the equivalent to fluid.
This powerful idea is the heart of digital circuitry today. Transistors come in a variety of types, with the most popular being MOSFETs and BJTs, but the list continues with lots of others basically derivatives of the two most popular ones.
Bipolar indicates that both the electrons and holes take part in the transistor's operation. Much more can be said about this wonderful invention, but that's a long story outside the scope of this article. Hydraulic analogy - the BJT as a current valve[ edit ] Valve - a variable water bottleneck As we saw in some of the other articles of Circuit Idea, hydraulic analogy is a powerful and intuitive concept for explaining electrical circuits.
Current flow hence the word "flow" can be represented by the flow of a fluid. Usually, when we want some fluid flowing at a constant rate, e. Potentiometer - a mechanically controlled current bottleneck A bottleneck consider the name is the point that has the lowest throughput, thus determining the maximum flow capacity.
Bottlenecks can be found not only in hydraulic stuff, but in virtually any system imaginable.This is an implementation of the Hypertext Transfer Protocol version 2 in C. The framing layer of HTTP/2 is implemented as a reusable C library.
On top of that, we have implemented an HTTP/2 client, server and proxy.
|Using XML Source – SSIS Team Blog||A Look at Journalists' Use of Anonymous Sources share Print Here's a guide to how and why American news reporters use "sources" to add information and details to their stories, in question-and-answer format:|
We have also developed load test and benchmarking tools for HTTP/2. An HPACK. A few more try to detect plagiarism by reading term-papers specifically for plagiarism, while the latter method might be not very effective in detecting plagiarism – especially when plagiarism from unfamiliar sources needs to be detected.
Last year's haul sank 15% to 53, tons, according to the JF Zengyoren national federation of fishing cooperatives. The squid catch has fallen by half in just two years. The previous low was plumbed in Lighter catches have been blamed on changing sea temperatures, which impedes the spawning.
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